Device for locking the steering spindle of a vehicle

ABSTRACT

A lock for irrotationally locking a motor-vehicle steering column enclosed by a tubular housing, the lock including a lock element displaceable to-and-fro between a locked and a released position and further a drive motor driving the locking element. For greater compactness, to offer enhanced security against theft, and to leave unhampered the telescoping of the steering pillar composed of steering column and tubular housing, further to reduce the danger of knee injury in case of accident, the locking element is mounted in the vicinity of the steering-wheel side end of the steering column inside the tubular housing, and the drive motor is mounted next to the foot-space side end of the steering column, and the drive motor cooperates with the locking element through a connecting element arrange inside the tubular housing.

BACKGROUND OF THE INVENTION

A. Field

The invention relates to a lock for irrotationally locking amotor-vehicle steering column enclosed by a tubular housing, said lockbeing fitted with a locking element displaceable in a to-and-fro mannerbetween a locked and a released position and with a drive motor drivingsaid locking element.

B. Related Art

A number of different designs already are known for means irrotationallylocking motor-vehicle steering columns.

Illustratively, as regards one design of the prior art, the lockingelement and the said drive motor are configured at the lowersteering-column end within a common housing. The steering column runsthrough the associated tubular housing, and through an opening in ametal floor panel of the motor vehicle and through said common housingscrewed onto the metal floor panel on the side away from said tubularhousing. The locking element encloses the steering column and issupported in axially displaceable but irrotational manner in said commonhousing and is fitted with locking teeth which may be made to mesh withmatching locking teeth of the steering column. Said drive motor is anelectric motor affixed to the inside of said common housing andcooperates by a mechanical linkage or by a lever with said lockingelement (EP 0 265 826 B).

In another known design of the kind of lock discussed herein, thelocking element and the drive motor are mounted close to one another andoutside the tubular housing enclosing the steering column. The lockingelement is in the shape of a bush and is mounted on the tubular housingin an axially displaceable manner and is fitted with at least oneresilient locking tooth that can be made to mesh with rigid lockingteeth of the steering column. Said drive motor is an electric motorexternally affixed to the tubular housing and by means of a cam-collarcooperates with the locking element in order to displace the latteragainst the force of a helical compression spring enclosing the steeringcolumn in a manner such that the locking element's locking tooth can bedisengaged from the steering column's locking teeth to allow rotation ofthe steering column. The cam-collar is rotatably supported on thetubular housing and is fitted with circumferential teeth meshing with apinion affixed on the shaft of the electric motor (DE 195 00 682 C).

Again a design of the above discussed type of lock is known wherein thelocking element and the drive motor are configured near each other in acommon housing through which the steering column runs. The lockingelement consists of a shaft rotatably supported inside the housing andfitted with two radially projecting locking protrusions. The shaft runstangentially relative to a locking ring which is affixed to the steeringcolumn and which is fitted with locking teeth with which the shaft'slocking protrusions can be made to engage. The drive motor is anelectric motor affixed in the housing and cooperating via a gearing unitwith said shaft (DE 196 21 326 C).

BRIEF SUMMARY OF THE INVENTION

The objective of the present invention is a lock of the initiallymentioned kind which is characterized by compactness, by offeringextraordinary vehicle theft-protection, by unhampered ability totelescope of the steering pillar composed of steering column and tubularhousing, and by preserving the driver in the event of accident from kneeinjuries because it is located outside the region containing the knees.

An illustrative embodiment of the lock of the invention is describedbelow in relation to the attached drawings.

FIG. 1 is a side view in partly longitudinal section, the lockingelement being in its locked position, and

FIG. 2 is a view similar to that of FIG. 1, but with the locking elementbeing in its released position.

DETAILED DESCRIPTION

The shown lock is used to irrotationally lock a motor-vehicle steeringcolumn 1 and it is fitted with a locking element 2 which can be movedto-and-fro between the locked position of FIG. 1 and the releasedposition of FIG. 2 and is driven by drive motor 3.

The steering column 1 is enclosed between its two ends 4, 5 by a tubularhousing 6. The motor-vehicle steering wheel is mounted on the end 4 ofthe steering column 1 on the left in FIGS. 1 and 2. The end 5 of thesteering column 1 shown on the right in FIGS. 1 and 2 is connected nearthe motor-vehicle foot space to said vehicle's steering gear unit.

The locking element 2 is mounted in the vicinity of the steering-wheelside end 4 of the steering column 1 within the tubular housing 6. Thedrive motor 3 is mounted next to the foot-space side end 5 of thesteering column 1, namely outside the tubular housing 6. The drive motor3 cooperates by a connecting element 8 with the locking element 2, saidconnecting element being mounted inside said tubular housing 6.

The locking element 2 is in the form of a bush and encloses the steeringcolumn 1, being supported inside the tubular housing 6 in an axiallydisplaceable but irrotational manner, as a result of which the lockingelement 2 is prevented from rotating inside the tubular housing 6 butcan move to-and-fro along the steering column 1. The locking element 2is conical at the left end 9 as shown in FIGS. 1 and 2 and is fitted atthe end 9, which tapers toward the steering-wheel side end 4 of thesteering column 1, with circumferentially equally spaced outer lockingteeth 10 cooperating with corresponding locking teeth 11 of the steeringcolumn 1.

The locking teeth 11 of the steering column 1 are provided on a collar12 affixed to said steering column 1. The collar 12 is fitted at the end13 adjacent to the locking element 2 with a conical borehole 14receiving the conical end 9 of the locking element 2. The locking teeth11 are circumferentially evenly spaced in the borehole 14 of the collar12, said borehole 14 tapering like the end 9 of the locking element 2toward the steering-wheel side end 4 of the steering column 1.

The locking element 2 is loaded by a helical compression spring 15toward the collar 12 of the steering column 1. This helical compressionspring 15 encloses the steering column 1 at that side of the lockingelement 2 which is away from the collar 12 and rests by one end againstthe end surface 16 of the locking element 2, which end surface 16 facesthe foot-space side end 5 of said column 1, and it rests by its otherend against a ring 17 affixed in the tubular housing 6.

The connecting element 8 between the drive motor 3 and the lockingelement 2 is in the form of an elongated plate which runs parallel tothe steering column 1 within the tubular housing 6 and is supported inan axially displaceable manner in a groove 18 of the tubular housing 6.The drive motor 3 cooperates with the right end 19 shown in FIGS. 1 and2 of the connecting element 8 which in turn cooperates with the left end20 shown in FIGS. 1 and 2 by means of a U-shaped pivoting bail 21 withthe locking element 2.

The U-shaped pivotable bail 21 is received in an external annular groove22 of the locking element 2 and encloses the locking element 2 fromabove in FIGS. 1, 2. The pivotable bail 21 comprises two side legs 23and a crossbar 24 linking the two legs 23. By its adjacent end 20, theconnecting element 8 acts on the two free ends 25 of the legs 23. Thepivotable bail 21 is pivotably supported on the tubular housing 6 atthat side of the locking element 2 which is away from the connectingelement 8, namely by means of a protrusion 26 projecting from the centerof the crossbar 24 and pointing away from the legs 23 and entering anaperture 27 of the tubular housing 6. On that side where the connectingelement 8 and the helical compression spring 15 are situated, andbetween their free ends 25 and the crossbar 24, the two legs 23 each arefitted with a convex boss 28 resting against the adjacent side surface29 of the annular groove 22.

The drive motor 3 is an electric motor cooperating by means of a gearunit 30, a slider 31 and a two-arm pivot lever 32 with the connectingelement 8. The drive motor 3, the gearing unit 30, the slider 31 and thepivot lever 32 are mounted in a common housing 33 which is affixedexternally to the tubular housing 6, that is at its foot-space side end34. The pivot lever 32 is pivotably supported on an arbor 35 mounted inthe housing 33 in such manner as to rest by one end 36 against theslider 31 and to engage by the other end 37 in a recess 38 on theadjacent end 19 of the connecting element 8.

The shown lock irrotationally locking the motor-vehicle steering column1 operates as follows:

The steering column 1 is shown locked in FIG. 1. The locking element 2assumes its locked position wherein its locking teeth 10 engage the gapsbetween the locking teeth 11 of the steering column 1, as a result ofwhich this steering column 1 is coupled to the tubular housing 6 withinwhich it is irrotational. To unlock the steering column 1, the drivemotor 3 is turned ON in such a way that, by means of the gear unit 30and the slider 31, it shall pivot the pivot lever 32 in the direction ofthe arrow A. In the process the pivot lever 32 displaces the connectingelement 8 in the direction of the arrow B and said connecting element 8in turn pivots the pivotable bail 21 in the direction of the arrow C. Inthe process, the pivotable bail 21 displaces the locking element 2 inthe direction of the arrow D against the loading from the helicalcompression spring 15 into its released position wherein the lockingteeth 10 of the locking element 2 are disengaged from the locking teeth11 of the steering column 1, and as a result the steering column 1 nowcan be rotated inside the tubular housing.

Consequently the state shown in FIG. 2 has been achieved. In order torelock the steering column 1, the drive motor 3 will be powered next, asa result of which the pivot lever 32, the connecting element 8, thepivotable bail 21 and the locking element 2, biased by the helicalcompression spring 15, respectively are displaced in the direction ofthe arrow A′, B′, C′ and D′ and thereby the state of FIG. 1 is restored.

What is claimed is:
 1. A lock for irrotationally locking an elongatedmotor-vehicle steering column (1) enclosed by an elongated tubularhousing (6) and having a steering wheel side end (4) located towards onelongitudinal end of the column (1) and a longitudinally spaced footspace side end (5) located towards an opposed longitudinal end of thecolumn (1), said lock being fitted with a locking element (2)displaceable to-and-fro between a locked and a released position andfurther with a drive motor (3) to drive the locking element (2), whereinthe locking element (2) is mounted in the vicinity of the steering-wheelside end (4) of the steering column (1) within the tubular housing (6)and wherein the drive motor (3) is mounted next to the foot-space sideend (5) of the steering column (1) longitudinally spaced from saidlocking element and further wherein the drive motor (3) cooperates withthe locking element (2) by means of a connecting element (8) arranged soas to extend longitudinally inside the tubular housing (6).
 2. Lock asclaimed in claim 1, wherein the locking element (2) is formed in theshape of a bush and is fitted with locking teeth (10) and encloses thesteering column (1) and is axially displaceable in a manner such that inthe locked position the locking teeth (10) lock the steering column (1)to the tubular housing (6).
 3. Lock as claimed in claim 2, wherein thebush-shaped locking element (2) is supported in irrotational but axiallyfreely displaceable manner inside the tubular housing (6) and whereinits locking teeth (10) cooperate with matching locking teeth (11)connected to the steering column (1).
 4. Lock as claimed in claim 2,wherein the connecting element (8) cooperates by means of a U-shapedpivotable bail (21) with the bush-shaped locking element (2), said bail(21) enclosing said locking element (2) and being pivotably supported onthe tubular housing (6) at the center of a crossbar (24) of the bail(21) on the side of the locking element (2) away from the connectingelement (8), the connecting element (8) acting on the free ends (25) ofthe two legs (23) of the pivotable bail (21) and the legs (23) in turnacting between their free ends (25) and the crossbar (24) of thepivotable bail (21) on the locking element (2).
 5. Lock as claimed inclaim 1, wherein the connecting element (8) directly cooperates with thelocking element (2).
 6. Lock as claimed in claim 1, wherein the lockingelement (2) is spring-loaded into the locked position.
 7. Lock asclaimed in claim 6, wherein the locking element (2) is formed in theshape of a bush and is fitted with locking teeth (10) and encloses thesteering column (1) and is axially displaceable in a manner such that inthe locked position the locking teeth (10) lock the steering column (1)to the tubular housing (6), and further wherein the bush-shaped lockingelement (2) is biased by a helical compression spring (15) into thelocked position, said spring (15) enclosing the steering column (1) andresting on one hand on the tubular housing (6) and on the other hand onthe locking element (2).
 8. Lock as claimed in claim 1, wherein thedrive motor (3) is an electric motor.
 9. Lock as claimed in claim 1,wherein the connecting element (8) is an elongated plate which isaxially displaceable parallel to the steering column (1).
 10. Lock asclaimed in claim 9, wherein the drive motor (3) cooperates by means of atwo-arm pivot lever (32) with the connecting element (8), said lever(32) being pivotable about an arbor (35) affixed to the tubular housing(61).
 11. Lock as claimed in claim 10, wherein the tubular housing (6)has a foot space side end (34) and wherein the drive motor (3) and thepivoting lever (32) are mounted in a common housing (33) which isexternally affixed to the foot-space side end (34) of the tubularhousing (6) and which is provided with the pivot arbor (35) of thepivoting lever (32).